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The GetParameterValue function returns the value of a named parameter within a SIP header string.


string GetParameterValue(
  string headerString,
  string parameterName



A header value that contains the parameter whose value is returned, as a string. For example, GetParameterValue("To: \"Display Name\" <>;param1=value1", "param1") returns "value1", where "param1" is the parameter name. (Note that the double quotes around the display name must be escaped if a literal is passed directly, rather than the output of another function, such as GetHeaderValues.)


The name of the parameter whose value is returned. In the example above, the parameter name is param1.

Return Values

Returns a string containing the value of the named parameter. Returns null if requested data is not found.


Header strings can be obtained by calling GetHeaderValues. A parameter that does not have a corresponding value (such as "lr") will not be returned. Valueless parameters should be handled by a managed code application.